Window shade system using adjustable angle involute gear

ABSTRACT

An involute gear bracket system includes first and second involute gears. Each includes a circular base and a plurality of gear teeth extending outward from an outer region of a surface and evenly spaced apart from each other along a plurality of locations on the outer region of the surface. The shape of each gear tooth is defined by a varying cross-sectional involute profile, wherein starting from a first involute profile that is in a plane parallel to the surface of the circular base and extending outward from a center of the circular base, each location on the first involute profile is rotated about a corresponding axis while traversing a path defined by a corresponding imaginary ray extending from the center of the circular base to that location, the corresponding axis being tangential to an imaginary circle that encompasses the inner region of the surface and perpendicular to the corresponding imaginary ray. A first bracket is coupled to a first pivot located at a first distance from the central axis of the first involute gear. A second bracket is coupled to a second pivot and rotatable about the second pivot at least within a second range of angles. The first and second pivots are arranged relative to each other and relative to the central axes of the first and second involute gears, respectively, such that the gear tooth of the first involute gear meshes with the gear tooth of the second involute gear at a corresponding angle within a second range of angles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S.Provisional Patent Application No. 62/219,522, filed Sep. 16, 2015, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Technical Field

The present embodiments relates to window shading and, moreparticularly, to window shading systems that incorporate gearing such asinvolute type gears.

Background Art

In many applications, motor driven window roller shades typically needto be placed with the end of one shade close to the end of another shadeto avoid having gaps that can permit light to enter. Therefore, insteadof driving each roller shade with its own motor, a single motor isconnected to an end of one of the roller shades to directly drive thatshade, and an adjoining roller shade is driven by a meshing a gearattached to the other end of the first roller shade with a gear attachedto the adjacent end of the next roller shade. In this manner, two ormore roller shades may be driven by a single motor.

In some applications, the adjacent roller shades are arranged along astraight line. However, in other applications, each roller shade may bearranged at angle with respect to its adjacent shade. Therefore, eachsuch arrangement could require specific pairs of gears that mesh atangles different than those required by another arrangement. To avoidthe cost of making a particular set of gears for each application, it isdesirable to provide a pair of gears that can mesh at a range of angles.

Moreover, at the time of installation, there may be minor differencesbetween the angles at which the roller shades are designed to intersectand the actual angles at which they intersect. It is therefore furtherdesirable to provide a pair of gears that are suitable for use in thepresence of such differences.

Conventional spur gears have a driving shaft and a driven shaft with aplurality of teeth, respectively, for gearing with each other inparallel so that only the ratio of rotation and the direction of therotation are changeable. However, the gearing intersection angle of therotation of the gears is determined when the gears are designed andmanufactured. Once the gearing intersection angle is determined, theangle of the rotation cannot change. That is, the gearing intersectionangle is not variable.

To provide a variable gearing intersection angle, some prior systemshave used a pair of semi-spherical gears. The driving shaft and thedriven shaft are each provided with a semi-spherical body member havinggear teeth and grooves which are longitudinally and radially arranged sothat the gears may engage at any of a range of intersection angles.However, the shape of semi-spherical gears does not permit the ends ofthe roller shades to be placed sufficiently close to each other.Additionally, the size needed to provide sufficient torque tosequentially drive several roller shades may further increase the sizeof the gears needed.

Involute gears are some of the most widely used gears in industry. In aninvolute gear, the profiles of the teeth are involutes of a circle. Thecontact between two mating involute gear teeth occurs at a singleinstantaneous point where two involutes of the same spiral hand meet andmoves along a fixed plane of contact irrespective of thecenter-to-center distance of the gears. Thus involute gears can handlecenter shifts and provide greater assembly flexibility. Moreover, thecontact surface between the gears is always perpendicular to the planeof contact, thus helping reduce torque variation.

It is therefore desirable to provide involute gears that can mesh at anyangle within a desired range of angles yet are capable of, for example,minimizing the separation between the ends of a pair of motorized rollershades.

SUMMARY OF THE INVENTION

It is to be understood that both the general and detailed descriptionsthat follow are exemplary and explanatory only and are not restrictiveof the embodiments.

DISCLOSURE OF INVENTION

An aspect is an involute gear bracket system, comprising (a) first andsecond involute gears, each including: (i) a circular base having asurface that includes an inner region and an outer region and that isrotatable about a central axis that is perpendicular to a center of thesurface; and (ii) a plurality of gear teeth extending outward from theouter region of the surface and being evenly spaced apart from eachother along a plurality of locations on the outer region of the surface,the shape of each gear tooth being defined by a varying cross-sectionalinvolute profile, wherein starting from a first involute profile that isin a plane parallel to the surface of the circular base and extendingoutward from a center of the circular base, each location on the firstinvolute profile is rotated about a corresponding axis while traversinga path defined by a corresponding imaginary ray extending from thecenter of the circular base to that location in the first involuteprofile, the corresponding axis being tangential to an imaginary circlethat encompasses the inner region of the surface and perpendicular tothe corresponding imaginary ray; (b) a first bracket coupled to a firstpivot and rotatable about the first pivot at least within a first rangeof angles, the first involute gear being rotatably coupled to the firstbracket such that the first involute gear is rotatable about its centralaxis, the first pivot being located at a first distance from the centralaxis of the first involute gear; and (c) a second bracket coupled to asecond pivot and rotatable about the second pivot at least within asecond range of angles, the second involute gear being rotatably coupledto the second bracket such that the second involute gear is rotatableabout its central axis, (d) wherein the first and second pivots arearranged relative to each other and relative to the central axes of thefirst and second involute gears, respectively, such that for any anglewithin the first range of angles, the gear tooth of the first involutegear meshes with the gear tooth of the second involute gear at acorresponding angle within the second range of angles.

According to a further aspect, an involute gear bracket system,comprises: (a) first and second involute gears, each including: (i) acircular base having a surface that includes an inner region and anouter region and that is rotatable about a central axis that isperpendicular to a center of the surface; and (ii) a plurality of gearteeth extending outward from the outer region of the surface and beingevenly spaced apart from each other along a plurality of locations onthe outer region of the surface, the shape of each gear tooth beingdefined by a varying cross-sectional involute profile, wherein startingfrom a first involute profile that is in a plane parallel to the surfaceof the circular base and extending outward from a center of the circularbase, each location on the first involute profile is rotated about acorresponding axis while traversing a path defined by a correspondingimaginary ray extending from the center of the circular base to thatlocation on the first involute profile, the corresponding axis beingtangential to an imaginary circle that encompasses the inner region ofthe surface and perpendicular to the corresponding imaginary ray; (b) aback plate; (c) a first bracket coupled to the back plate at a firstpivot and rotatable about the first pivot at least within a first rangeof angles, and including a first gear mounting portion, the firstinvolute gear being rotatably coupled to the first gear mounting portionsuch that the first involute gear is rotatable about its central axis,the first pivot being located at a first distance from the central axisof the first involute gear; and (d) a second bracket coupled to the backplate at a second pivot and rotatable about the second pivot at leastwithin a second range of angles, and including a second gear mountingportion, the second involute gear being rotatably coupled to the secondgear mounting portion such that the second involute gear is rotatableabout its central axis, (e) wherein the first pivot is locatedtangential to the imaginary circle of the first involute gear and at afirst distance from the central axis of the first involute gear, thesecond pivot is located tangential to the imaginary circle of the secondinvolute gear and at a second distance from the central axis of thesecond involute gear and is parallel to the first pivot, and the firstbracket and the second bracket are interconnected such that a firstangle formed between the inner region of the surface of the first gearand a mid-plane perpendicular to and bisecting an imaginary lineextending from the first pivot to the second pivot, and a second angleformed between the inner region of the surface of the second gear andthe mid-plane, each have a same value, so that for any angle within thefirst range of angles, the gear tooth of the first involute gear mesheswith the gear tooth of the second involute gear at a corresponding anglewithin the second range of angles.

According to another aspect, a window shade system, comprises: (a) afirst bracket having a window frame mounting portion attachable to afirst window frame, and a receiving portion for receiving an end of afirst window shade roller of a first window shade; (b) a second brackethaving a window frame mounting portion attachable to a second windowframe, and a receiving portion for receiving an end of a second windowshade roller of a second window shade; (c) first and second involutegears, each including: (i) a circular base having a surface thatincludes an inner region and an outer region and that is rotatable abouta central axis that is perpendicular to a center of the surface; and(ii) a plurality of gear teeth extending outward from the outer regionof the surface and being evenly spaced apart from each other along aplurality of locations on the outer region of the surface, the shape ofeach gear tooth being defined by a varying cross-sectional involuteprofile, wherein starting from a first involute profile that is in aplane parallel to the surface of the circular base and extending outwardfrom a center of the circular base, each location on the first involuteprofile is rotated about a corresponding axis while traversing a pathdefined by a corresponding imaginary ray extending from the center ofthe circular base to that location in the first involute profile, thecorresponding axis being tangential to an imaginary circle thatencompasses the inner region of the surface and perpendicular to thecorresponding imaginary ray; (d) the first bracket being coupled to afirst pivot and rotatable about the first pivot at least within a firstrange of angles, the first involute gear being rotatably coupled to thereceiving portion of the first bracket such that the first involute gearand the first window shade roller are rotatable about the central axisof the first involute gear, the first pivot being located at a firstdistance from the central axis of the first involute gear; and (e) thesecond bracket being coupled to a second pivot and rotatable about thesecond pivot at least within a second range of angles, the secondinvolute gear being rotatably coupled to the receiving portion of thesecond bracket such that the second involute gear and the second windowshade roller are rotatable about the central axis of the second involutegear, the second pivot being located at a second distance from thecentral axis of the second involute gear; and (f) the first and secondpivots are arranged relative to each other and relative to the centralaxes of the first and second involute gears, respectively, such that forany angle within the first range of angles, the gear tooth of the firstinvolute gear meshes with the gear tooth of the second involute gear ata corresponding angle within the second range of angles.

According to yet another aspect, a window shade system, comprises: (a) aback plate; (b) a first bracket coupled to the back plate at a firstpivot and having a window frame mounting portion attachable to a firstwindow frame, and a receiving portion for receiving an end of a firstwindow shade roller of a first window shade; (c) a second bracketcoupled to the back plate at a first pivot and having a window framemounting portion attachable to a second window frame, and a receivingportion for receiving an end of a second window shade roller of a secondwindow shade; (d) first and second involute gears, each including: (i) acircular base having a surface that includes an inner region and anouter region and that is rotatable about a central axis that isperpendicular to a center of the surface; and (ii) a plurality of gearteeth extending outward from the outer region of the surface and beingevenly spaced apart from each other along a plurality of locations onthe outer region of the surface, the shape of each gear tooth beingdefined by a varying cross-sectional involute profile, wherein startingfrom a first involute profile that is in a plane parallel to the surfaceof the circular base and extending outward from a center of the circularbase, each location on the first involute profile is rotated about acorresponding axis while traversing a path defined by a correspondingimaginary ray extending from the center of the circular base to thatlocation in the first involute profile, the corresponding axis beingtangential to an imaginary circle that encompasses the inner region ofthe surface and perpendicular to the corresponding imaginary ray; (e)the first bracket being rotatable about the first pivot at least withina first range of angles, the first involute gear being rotatably coupledto the receiving portion of the first bracket such that the firstinvolute gear and the first window shade roller are rotatable about thecentral axis of the first involute gear, the first pivot being locatedat a first distance from the central axis of the first involute gear;and (f) the second bracket being rotatable about the second pivot atleast within a second range of angles, the second involute gear beingrotatably coupled to the receiving portion of the second bracket suchthat the second involute gear and the second window shade roller arerotatable about the central axis of the second involute gear, the secondpivot being located at a second distance from the central axis of thesecond involute gear; and (g) wherein the first pivot is tangential tothe imaginary circle of the first involute gear and is located at afirst distance from the central axis of the first involute gear, thesecond pivot is tangential to the imaginary circle of the secondinvolute gear and is located at a second distance from the central axisof the second involute gear and is parallel to the first pivot, and thefirst bracket and the second bracket are interconnected such that afirst angle formed between the inner region of the surface of the firstgear and a mid-plane perpendicular to and bisecting an imaginary lineextending from the first pivot to the second pivot, and a second angleformed between the inner region of the surface of the second gear andthe mid-plane, each have a same value, so that for any angle within thefirst range of angles, the gear tooth of the first involute gear mesheswith the gear tooth of the second involute gear at a corresponding anglewithin the second range of angles.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying figures further illustrate the present embodiments.

The components in the drawings are not necessarily drawn to scale,emphasis instead being placed upon clearly illustrating the principlesof the present embodiments. In the drawings, like reference numeralsdesignate corresponding parts throughout the several views.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 shows a top view of an involute gear in accordance with anembodiment.

FIGS. 2A-2E are schematic diagrams showing an example of a shape of agear tooth of the involute gear in accordance with an embodiment.

FIGS. 3A-3B are schematic diagrams showing an example of another shapeof a gear tooth of the involute gear in accordance with anotherembodiment.

FIG. 4 shows an enlarged top view of the gear tooth in accordance withan embodiment.

FIG. 5A shows a front view of an arrangement of a pair of involute gearsin accordance with an embodiment; and FIG. 5B depicts an enlargedportion of the top view of the pair of the involute gears shown in FIG.5A.

FIG. 6A depicts a side perspective view of another arrangement of thepair of involute gears shown in FIG. 5A and includes a cross-sectionalview of a mating portion of the involute gears; and FIG. 6B shows aclose-up view of the cross-sectional portion shown in FIG. 6A.

FIG. 7 depicts a perspective view of a further arrangement of theinvolute gears shown in FIG. 5A and includes a cross-sectional view ofthe involute gears.

FIG. 8 shows a front perspective view of a still further arrangement ofthe involute gears shown in FIG. 5A.

FIG. 9 shows a side perspective view of yet another arrangement of theinvolute gears shown in FIG. 5A.

FIG. 10 depicts a front perspective view of a configuration of amounting bracket system in accordance with an embodiment.

FIG. 11 shows a top perspective view of the configuration of themounting bracket system shown in FIG. 10.

FIG. 12 depicts a front perspective view of another configuration of themounting bracket system shown in FIG. 10.

FIG. 13 shows a top perspective view of the configuration of themounting bracket system shown in FIG. 12.

FIG. 14 shows a top perspective view of yet another configuration of themounting bracket system shown in FIG. 10.

FIG. 15 depicts a back perspective view of the configuration of themounting bracket system shown in FIG. 10.

FIG. 16 depicts a back perspective view of a further configuration ofthe bracket system shown in FIG. 10.

FIG. 17A shows a front perspective view of a window shade system inaccordance with an embodiment, and FIG. 17B shows in greater detail themounting bracket system part of the window shade system depicted in FIG.17A.

FIG. 18A shows a frontal perspective view from above of the window shadesystem depicted in FIG. 17A, and FIG. 18B shows in greater detail themounting bracket system part of the window shade system depicted in FIG.18A.

FIG. 19A shows a frontal perspective view from below of the window shadesystem depicted in FIG. 17A, and FIG. 19B shows in greater detail themounting bracket system part of the window shade system depicted in FIG.19A.

FIG. 20 shows a bottom perspective view of the window shade systemdepicted in FIG. 17A

DETAILED DESCRIPTION OF THE INVENTION

The present embodiments provide involute gears in which a pair of gearsis capable of meshing at any of a range of gearing intersection angles.The shape of the gear teeth is defined by an involute outer profile thatcollapses inward with decreasing distance from the center of the gear.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words ‘comprise’, ‘comprising’, and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to”.

List of Reference Numbers for the Major Elements in the Drawing

The following is a list of the major elements in the drawings innumerical order.

-   -   100 first involute gear    -   102 inner region (of first involute gear 100)    -   104 outer region (of first involute gear 100)    -   106 gear tooth (of first involute gear 100)    -   108 circular base (of first involute gear 100)    -   110 first surface (of first involute gear 100)    -   120 second involute gear 120    -   122 inner region (of second involute gear 120)    -   124 outer region (of second involute gear 120)    -   126 gear tooth (of second involute gear 120)    -   128 circular base (of second involute gear 120)    -   130 first surface (of second involute gear 120)    -   208 imaginary circle    -   210 outer surface (of gear tooth)    -   212 involute outer profile (of gear tooth)    -   214 center of involute gear    -   216 width (of involute outer profile 212)    -   218 length (of involute outer profile 212)    -   220 axes of rotation (of locations on involute profile)    -   222 end portion (of involute outer profile 212)    -   224 imaginary rays (from center of involute gear to location on        involute profile)    -   230 a, 230 b pivots    -   306 gear tooth    -   622 cross-section (of gear tooth 106)    -   624 cross-section (of gear tooth 126)    -   706 first angle    -   710 mid-plane    -   716 second angle    -   1000 mounting bracket    -   1010 first plate    -   1011 pivoting portion (of first plate 1010)    -   1012 back wall (of first plate 1010)    -   1014 side wall (of first plate 1010)    -   1015 interlocking end gears (of pivoting portion 1011)    -   1016 first pivot element    -   1018 top wall (of first plate 1010)    -   1020 second plate    -   1021 pivoting portion (of second plate 1020)    -   1022 back wall (of second plate 1020)    -   1024 wall mounting portion (of second plate 1020)    -   1025 interlocking end gears (of pivoting portion 1021)    -   1026 second pivot element    -   1028 top wall (of second plate 1020)    -   1030 back plate    -   1040 rotation mount (of first plate 1010)    -   1042 rotation mount (of second plate 1020)    -   1044 back side opening (of first gear 100)    -   1046 back side opening (of second gear 120)    -   1050 cut-away region (of top wall 1018)    -   1060 cut-away region (of top wall 1028)    -   1700 window shade system    -   1701 first window frame    -   1702 window frame head (of first window frame 1701)    -   1704 inner surface (of window frame head 1710)    -   1710 window shade roller (of first window frame 1701)    -   1712 window shade (of first window frame 1700)    -   1714 end bracket (of first window frame 1701)    -   1720 second window frame    -   1722 window frame head (of second window frame 1720)    -   1724 inner surface (of window frame head 1722)    -   1730 window shade roller (of second window frame 1720)    -   1732 window shade (of second window frame 1720)    -   1734 end bracket (of second window frame 1720)

MODE(S) FOR CARRYING OUT THE INVENTION

The embodiment described herein in the context of an involute gearsystem, but is not limited thereto, except as may be set forth expresslyin the appended claims.

Referring first to FIG. 1, a first involute gear 100 is depicted inaccordance with an embodiment. The first involute gear 100 includes acircular base 108 having a first surface 110 which is divided into acentral, inner region 102 and an outer region 104 which encloses theinner region 102. A plurality of gear teeth 106 are arranged atrespective locations on the first involute gear 100. Each one of thegear teeth extends upwardly, in part, and outwardly, in part, primarilyfrom the outer region 104 of the first surface.

FIGS. 2A-2E illustrate the manner in which the shape of a gear tooth 106is defined for the involute gear 100 in accordance with an embodiment.FIG. 2A shows a top view of a cut-away portion of the inner region 102and the outer region 104 of the involute gear 100. An imaginary circle208 is defined in the outer region 104. The imaginary circle isconcentric with the involute gear 100 and encloses the inner region 102.

Each gear tooth 106 of the involute gear 100 is disposed along theimaginary circle 208. The outer shape of the gear tooth 106 may bedefined starting from an involute outer profile 212 which is shown in aplane parallel to the surface of the inner region 102 and extendingoutward from the center of the gear.

For each location on the involute outer profile 212, a correspondingimaginary ray 224 may be drawn from the center 214 of the gear to thatlocation on the involute outer profile 212. FIG. 2B shows examples ofthe imaginary rays 224. Also, for each location on the involute outerprofile 212, a corresponding axis 220 is shown which is both tangentialto the imaginary circle 208 and perpendicular to its correspondingimaginary ray 224.

To define the outer profile of the gear tooth 106, each location on theinvolute outer profile 212 is rotated about its corresponding axis 220while traversing a path defined by its corresponding imaginary ray 224.FIG. 2C shows an example of one such location on the involute outerprofile 212 being rotated about its corresponding axis 220 in thismanner. Though a rotation of 180° about the axis 220 is shown, the angleof rotation may be any value greater or less than 180°. For example, arotation of 90° about the axis 220 is sufficient to allow for a 180°range of gearing angles.

FIG. 2D shows a top view of the gear tooth 106 after each location onthe involute outer profile 212 is rotated in the above-described manner,and FIG. 2E shows a side view of the gear tooth. Though the gear toothis depicted as being formed of straight line segments, a curved involuteprofile will generate a gear tooth having curved walls.

FIGS. 3A-3B depict another example of a gear tooth 306 in which theouter shape of the gear tooth 306 is defined by a 360° rotation of eachlocation on the involute outer profile 212 in the above manner.Alternatively, the gear tooth may be defined another range of rotationabout the axis and provide a different range of gearing angles.

FIG. 4 shows a top view of the gear tooth 106 formed by rotation in themanner described above. Though a bevel-shaped gear tooth is depicted,other involute shapes are also within the scope of the embodimentincluding more rounded shapes.

FIGS. 5A-5B depict a front view of an arrangement of a pair of involutegears in accordance with an embodiment. Referring to FIG. 5A, the firstinvolute gear 100 shown in FIG. 1 is depicted meshed with a secondinvolute gear 102 in which the outer shape of each gear tooth 126 isdefined in a manner similar to that of each gear tooth 106 of the firstinvolute gear 100. Namely, each gear tooth 126 is defined by rotating aninvolute outer profile about an axis in the manner described above inconnection with FIGS. 2A-2D and 3A-3B.

The second involute gear 120 includes a circular base 128 having aninner region 122 and an outer region 124 which comprise a first surface130 of the second involute gear 120. Extending from the outer region 124of the surface 130 are the plurality of gear teeth 126, each of whichextends upwards, in part, and outwards, in part, from the surface.Though the first involute gear 100 and the second involute gear 120 areshown having a same diameter, other embodiments having first and secondinvolute gears of unequal diameters are also within the scope of thedisclosure.

FIG. 5B is a close-up view of a portion of the meshed first and secondinvolute gears 100 and 102 shown in FIG. 5A. Particularly, the gearteeth 106 and 126 are shown in close up.

Additionally, in FIG. 5A, the first and second involute gears 100 and102 are arranged with the first surfaces of the gears disposed in a sameplane, that is, at a 180° gearing intersection angle. However, inaccordance with the embodiment, the first and second involute gears 100and 102 are able to mesh with each other at any of a range of angles.

FIGS. 6A-6B illustrate another arrangement of the pair of involute gears100, 120 shown in FIGS. 5A-5B in which the gear teeth 106 and 126 of theinvolute gears 100 and 120, respectively, are meshed at another anglewithin the 180° range of gearing angles. FIG. 6A also shows thecross-sections 622 and 624 of the gear teeth 106 and 126, respectively,when meshed at the depicted gearing angle. In accordance with anembodiment, the involute gear 100 is rotatable about a pivot 230 a whichis tangential to the imaginary circle 208 of the involute gear 100, andthe involute gear 120 is rotatable about a pivot 230 b which istangential to an imaginary circle (not shown) of the involute gear 120and parallel to the pivot 230 a. FIG. 6B is a close-up view of therespective cross-sections 622 and 624 of the gear teeth 106 and 126shown in FIG. 6A.

FIG. 7 show a further arrangement of the pair of involute gears 100, 120in which the gear teeth 106 and 126 are meshed at yet another anglewithin the 180° range of gearing angles. FIG. 7 also illustrates anexample of the conditions by which the involute gears 100, 120 mesh at arange of angles. Specifically, a distance from the pivot 230 aassociated with the involute gear 100 to the pivot 230 b associated withthe involute gear 120 is fixed. For example, the distance from the pivot230 a to the pivot 230 b may be twice the distance from each pivot 230 aor 230 b to the addendum of their associated gears. Further, a firstangle 706 formed between the inner region 102 of the surface 110 of thegear 100 and a mid-plane 710 perpendicular to and bisecting a distancefrom the pivot 230 a to the pivot 230 b, and a second angle 716 formedbetween the inner region 122 of the surface 130 of the gear 120 and themid-plane 170, each have a same value.

As depicted above, FIGS. 5A-5B show the involute gears 100, 120 meshingat a gearing intersection angle of 180° wherein the above conditions aremet. Moreover, when the above conditions are met, the involute gears100, 120 mesh at other gearing intersection angles as depicted in FIGS.6A-6B and 7.

FIG. 8 shows a side view of an arrangement of the involute gears 100,120 meshing at still another gearing angle, and FIG. 9 shows a side viewof an arrangement of the involute gears 100, 120 meshing at a gearingangle of 0°.

FIG. 10 shows a front perspective view of an example of a bracket system1000 in accordance with an embodiment. The bracket system 1000 may beused, for example, to enable a mounted first roller shade to drive anadjacently mounted roller shade at any of a range of angles between thetwo roller shades.

The bracket system 1000 incorporates, for example, the involute gears100 and 120 described above which are rotatably mounted to brackets 1010and 1020, respectively. The bracket 1010 may include a gear mountingportion 1012 and a wall mounting portion 1014 and is pivotally mountedabout a pivot element 1016 to a back plate 1030. The bracket 1020 mayinclude a gear mounting portion 1022 and a wall mounting portion 1024and is pivotally mounted about a pivot element 1026 to the back plate1030. The spacing of the pivots 1016 and 1026, and the angle relationsof the surfaces of the involute gears 100 and 120 with a mid-plane (notshown) between pivots 1016 and 1026 comply with the conditions describedabove in connection with FIG. 7 so that the involute gears 100 and 120can mesh at any of a range of gearing intersection angles about thepivots 1016 and 1026. For example, FIG. 10 shows the involute gears 100and 120 meshing at an acute angle.

FIG. 11 shows a top perspective view of the bracket system 1000 arrangedat the acute angle shown in FIG. 10.

FIG. 12 shows a front perspective view of an example of the bracketsystem 1000 of FIG. 10 in which the involute gears 100 and 120 mesh at a180° gearing intersection angle, and FIG. 13 shows a top view of thebracket system 1000 arranged at the gearing intersection angle.

FIG. 14 shows a top perspective view of the bracket system 1000 in whichthe involute gears 100 and 120 mesh at a gearing intersection angle of0°.

FIG. 15 depicts a back perspective view of the bracket system 1000 withthe involute gears 100 and 102 meshing at a 180° gearing intersectionangle. FIG. 15 also shows the rotation mounts 1040 and 1042 into whichthe involute gears 100 and 102 are respectively mounted in the brackets1010 and 1020. Openings 1044 and 1046 are defined in the back side ofthe involute gears 100 and 102, respectively, at the center of the gearsand are configured to receive an end of a roller shade or other elementthat is to be rotatably driven by the gears. Though hexagonal openingsare shown, other shapes are also suitable and within the scope of theembodiment.

FIG. 16 depicts a back perspective view of the bracket system 1000 andshows the involute gears 100 and 102 meshing at another gearingintersection angle.

FIGS. 17-20 illustrate an example of a window shade system 1700 whichincorporates the mounting bracket 1000 shown in FIGS. 10-16. Themounting bracket 1000 interconnects a first window shade 1712 with asecond window shade 1732 such that a motor (not shown) driving one ofthe first and second window shades also drives the other of the firstand second window shades regardless of the angle formed between theinvolute gears of the mounting bracket 1000. As a result, when the motordrives one of the first and second window shades to roll up that shade,the other shade concurrently rolls ups, and when the motor drives one ofthe first and second window shades to roll down that shade, the othershade concurrently rolls down. Though only two window shades are shown,additional shades may be driven by the same motor using additionalmounting brackets 1000 to a further widow shade to one of the first andsecond window shades.

FIGS. 17A-17B depict front perspective view of the example of the windowshade system 1700. A first window frame 1701 is disposed adjacent to asecond window frame 1720. The first and second window frames aredisposed at an angle with respect to each other. Though the two windowframes are shown arranged at an acute angle between them, the two windowframes may be arranged any of a range of angles, including beingarranged in the same plane (a 180° angle) or at a 90° angle.

A window shade roller 1710 of the first window shade 1712 is rotatablyattached to a window frame head 1702 of the first window frame 1701. Thewindow shade roller 1710 is rotatably coupled at one end to an endbracket 1714 which is in turn affixed to the window frame head 1702 ofthe first window frame 1701. The window shade roller 1710 is attached atanother end to an involute gear of the mounting bracket 1000.

A window shade roller 1730 of the second window shade 1732 is rotatablyattached to a window frame head 1722 of the second window frame 1720.The window shade roller 1730 is rotatably attached at one end to an endbracket 1734 which is in turn affixed to the window frame head 1722 ofthe second window frame 1720. The window shade roller 1730 is attachedat another end to another involute gear of the mounting bracket 1000.

FIG. 17B shows in greater detail the mounting bracket 1000 depicted inFIG. 17A together with cut-away portions of the window frame heads 1702and 1722 and of the window shade rollers 1710 and 1730. In FIG. 17B,like reference numerals to those of FIGS. 10-16 identify same parts ofthe mounting bracket 1000. The top wall 1028 of the second plate 1020 ofthe mounting bracket 1000 is affixed to the window frame head 1702 ofthe first window frame 1701. The wall mounting portion 1024 of thesecond plate 1020 may also be attached to another surface of the firstwindow frame 1701. The top wall 1018 of the first plate 1010 of themounting bracket 1000 is affixed to the window frame head 1722 of thesecond window frame 1720. The wall mounting portion 1014 of the firstplate 1012 may also be attached to another surface of the second windowframe 1720.

When one of the window shade rollers 1710, 1730 of the first window andsecond shades 1712, 1731 is rotated, such as using a motor (not shown),the end connected to one of the involute gears of the mounting bracket1000 similarly rotates and causes the other involute gear to rotate,which in turn rotates the window shade roller attached to that involutegear. In this manner, a motor driving one of the window shades may beused to drive one or more additional roller shades.

FIG. 18A shows a frontal perspective view from above of the window shadesystem 1700 depicted in FIG. 17A. FIG. 18B shows in greater detail themounting bracket 1000 as depicted in FIG. 18A together with cut-awayportions of the window frame heads 1702 and 1722 and of the window shaderollers 1710 and 1730.

FIG. 19A shows a frontal perspective view from below of the window shadesystem 1700 depicted in FIG. 17A. FIG. 19B shows in greater detail themounting bracket 1000 as depicted in FIG. 19A together with cut-awayportions of the window frame heads 1702 and 1722 and of the window shaderollers 1710 and 1730.

FIG. 20 shows a bottom perspective view of the window shade system 1700depicted in FIG. 17A.

In each of FIGS. 17A-17B, 18A-18B, 19A-19B and 20, like referencenumerals identify like parts.

Because the mounting bracket 1000 is operable any of a range of gearangles, such as from 0° to 180°, the mounting bracket 1000 is suitablefor use with adjacent windows at any of a corresponding range of angles.Therefore, the need for providing specific gear arrangements designedonly for a specific gear angle is eliminated.

INDUSTRIAL APPLICABILITY

To solve the aforementioned problems, the present embodiments provide aninvolute gear system and bracket system which permit adjacent motorizedroller shades to be driven by a single motor regardless of the anglebetween the adjacent roller shades.

ALTERNATE EMBODIMENTS

Alternate embodiments may be devised without departing from the spiritor the scope of the embodiments.

What is claimed is:
 1. An involute gear bracket system, comprising: (a)first and second involute gears, each including: (i) a circular basehaving a surface that includes an inner region and an outer region andthat is rotatable about a central axis that is perpendicular to a centerof the surface; and (ii) a plurality of gear teeth extending outwardfrom the outer region of the surface and being evenly spaced apart fromeach other along a plurality of locations on the outer region of thesurface, the shape of each gear tooth being defined by a varyingcross-sectional involute profile, wherein starting from a first involuteprofile that is in a plane parallel to the surface of the circular baseand extending outward from a center of the circular base, each locationon the first involute profile is rotated about a corresponding axiswhile traversing a path defined by a corresponding imaginary rayextending from the center of the circular base to that location in thefirst involute profile, the corresponding axis being tangential to animaginary circle that encompasses the inner region of the surface andperpendicular to the corresponding imaginary ray; (b) a first bracketcoupled to a first pivot and rotatable about the first pivot at leastwithin a first range of angles, the first involute gear being rotatablycoupled to the first bracket such that the first involute gear isrotatable about its central axis, the first pivot being located at afirst distance from the central axis of the first involute gear; and (c)a second bracket coupled to a second pivot and rotatable about thesecond pivot at least within a second range of angles, the secondinvolute gear being rotatably coupled to the second bracket such thatthe second involute gear is rotatable about its central axis, (d)wherein the first and second pivots are arranged relative to each otherand relative to the central axes of the first and second involute gears,respectively, such that for any angle within the first range of angles,the gear tooth of the first involute gear meshes with the gear tooth ofthe second involute gear at a corresponding angle within the secondrange of angles.
 2. The involute gear bracket system of claim 1, wherein(a) the first pivot is tangential to the imaginary circle of the firstinvolute gear and located at a first distance from the central axis ofthe first involute gear, (b) the second pivot is tangential to theimaginary circle of the second involute gear and located at a seconddistance from the central axis of the second involute gear and isparallel to the first pivot, and (c) a first angle formed between theinner region of the surface of the first gear and a mid-planeperpendicular to and bisecting an imaginary line extending from thefirst pivot to the second pivot, and a second angle formed between theinner region of the surface of the second gear and the mid-plane, eachhave a same value, so that for any angle within the first range ofangles, the gear tooth of the first involute gear meshes with the geartooth of the second involute gear at a corresponding angle within thesecond range of angles.
 3. The involute gear bracket system of claim 1,wherein the first bracket and the second bracket are interconnected suchthat movement of the first bracket about the first pivot causes acorresponding movement of the second bracket about the second pivot. 4.The involute gear bracket system of claim 1, wherein the first bracketincludes a gear mounting portion to which the first involute gear isrotatably coupled, and at least one surface mounting portion formounting the involute gear bracket system to a surface.
 5. The involutegear bracket system of claim 1, wherein the second bracket includes agear mounting portion to which the second involute gear is rotatablycoupled, and at least one surface mounting portion for mounting theinvolute gear bracket system to a surface.
 6. The involute gear bracketsystem of claim 1, further comprising: a back plate coupled to the firstbracket at the first pivot such that the first bracket is movable aboutthe first pivot and coupled to the second bracket at the second pivotsuch that the second bracket is movable about the second pivot.
 7. Theinvolute gear bracket system of claim 6, further comprising: at leastone first pivot element located at the first pivot, and at least onesecond pivot element located at the second pivot.
 8. An involute gearbracket system, comprising: (a) first and second involute gears, eachincluding: (i) a circular base having a surface that includes an innerregion and an outer region and that is rotatable about a central axisthat is perpendicular to a center of the surface; and (ii) a pluralityof gear teeth extending outward from the outer region of the surface andbeing evenly spaced apart from each other along a plurality of locationson the outer region of the surface, the shape of each gear tooth beingdefined by a varying cross-sectional involute profile, wherein startingfrom a first involute profile that is in a plane parallel to the surfaceof the circular base and extending outward from a center of the circularbase, each location on the first involute profile is rotated about acorresponding axis while traversing a path defined by a correspondingimaginary ray extending from the center of the circular base to thatlocation on the first involute profile, the corresponding axis beingtangential to an imaginary circle that encompasses the inner region ofthe surface and perpendicular to the corresponding imaginary ray; (b) aback plate; (c) a first bracket coupled to the back plate at a firstpivot and rotatable about the first pivot at least within a first rangeof angles, and including a first gear mounting portion, the firstinvolute gear being rotatably coupled to the first gear mounting portionsuch that the first involute gear is rotatable about its central axis,the first pivot being located at a first distance from the central axisof the first involute gear; and (d) a second bracket coupled to the backplate at a second pivot and rotatable about the second pivot at leastwithin a second range of angles, and including a second gear mountingportion, the second involute gear being rotatably coupled to the secondgear mounting portion such that the second involute gear is rotatableabout its central axis, (e) wherein the first pivot is locatedtangential to the imaginary circle of the first involute gear and at afirst distance from the central axis of the first involute gear, thesecond pivot is located tangential to the imaginary circle of the secondinvolute gear and at a second distance from the central axis of thesecond involute gear and is parallel to the first pivot, and the firstbracket and the second bracket are interconnected such that a firstangle formed between the inner region of the surface of the first gearand a mid-plane perpendicular to and bisecting an imaginary lineextending from the first pivot to the second pivot, and a second angleformed between the inner region of the surface of the second gear andthe mid-plane, each have a same value, so that for any angle within thefirst range of angles, the gear tooth of the first involute gear mesheswith the gear tooth of the second involute gear at a corresponding anglewithin the second range of angles.
 9. A window shade system, comprising:(a) a first bracket having a window frame mounting portion attachable toa first window frame, and a receiving portion for receiving an end of afirst window shade roller of a first window shade; (b) a second brackethaving a window frame mounting portion attachable to a second windowframe, and a receiving portion for receiving an end of a second windowshade roller of a second window shade; (c) first and second involutegears, each including: (i) a circular base having a surface thatincludes an inner region and an outer region and that is rotatable abouta central axis that is perpendicular to a center of the surface; and(ii) a plurality of gear teeth extending outward from the outer regionof the surface and being evenly spaced apart from each other along aplurality of locations on the outer region of the surface, the shape ofeach gear tooth being defined by a varying cross-sectional involuteprofile, wherein starting from a first involute profile that is in aplane parallel to the surface of the circular base and extending outwardfrom a center of the circular base, each location on the first involuteprofile is rotated about a corresponding axis while traversing a pathdefined by a corresponding imaginary ray extending from the center ofthe circular base to that location in the first involute profile, thecorresponding axis being tangential to an imaginary circle thatencompasses the inner region of the surface and perpendicular to thecorresponding imaginary ray; (d) the first bracket being coupled to afirst pivot and rotatable about the first pivot at least within a firstrange of angles, the first involute gear being rotatably coupled to thereceiving portion of the first bracket such that the first involute gearand the first window shade roller are rotatable about the central axisof the first involute gear, the first pivot being located at a firstdistance from the central axis of the first involute gear; and (e) thesecond bracket being coupled to a second pivot and rotatable about thesecond pivot at least within a second range of angles, the secondinvolute gear being rotatably coupled to the receiving portion of thesecond bracket such that the second involute gear and the second windowshade roller are rotatable about the central axis of the second involutegear, the second pivot being located at a second distance from thecentral axis of the second involute gear; and (f) the first and secondpivots are arranged relative to each other and relative to the centralaxes of the first and second involute gears, respectively, such that forany angle within the first range of angles, the gear tooth of the firstinvolute gear meshes with the gear tooth of the second involute gear ata corresponding angle within the second range of angles.
 10. The windowshade system of claim 9, wherein (a) the first pivot is tangential tothe imaginary circle of the first involute gear and is located at afirst distance from the central axis of the first involute gear, (b) thesecond pivot is tangential to the imaginary circle of the secondinvolute gear and is located at a second distance from the central axisof the second involute gear and is parallel to the first pivot, and (c)a first angle formed between the inner region of the surface of thefirst gear and a mid-plane perpendicular to and bisecting an imaginaryline extending from the first pivot to the second pivot, and a secondangle formed between the inner region of the surface of the second gearand the mid-plane, each have a same value, so that for any angle withinthe first range of angles, the gear tooth of the first involute gearmeshes with the gear tooth of the second involute gear at acorresponding angle within the second range of angles.
 11. The windowshade system of claim 9, wherein the first bracket and the secondbracket are interconnected such that movement of the first bracket aboutthe first pivot causes a corresponding movement of the second bracketabout the second pivot.
 12. The window shade system of claim 9, furthercomprising: a back plate coupled to the first bracket at the first pivotsuch that the first bracket is movable about the first pivot and coupledto the second bracket at the second pivot such that the second bracketis movable about the second pivot,
 13. A window shade system,comprising: (a) a back plate; (b) a first bracket coupled to the backplate at a first pivot and having a window frame mounting portionattachable to a first window frame, and a receiving portion forreceiving an end of a first window shade roller of a first window shade;(c) a second bracket coupled to the back plate at a first pivot andhaving a window frame mounting portion attachable to a second windowframe, and a receiving portion for receiving an end of a second windowshade roller of a second window shade; (d) first and second involutegears, each including: (i) a circular base having a surface thatincludes an inner region and an outer region and that is rotatable abouta central axis that is perpendicular to a center of the surface; and(ii) a plurality of gear teeth extending outward from the outer regionof the surface and being evenly spaced apart from each other along aplurality of locations on the outer region of the surface, the shape ofeach gear tooth being defined by a varying cross-sectional involuteprofile, wherein starting from a first involute profile that is in aplane parallel to the surface of the circular base and extending outwardfrom a center of the circular base, each location on the first involuteprofile is rotated about a corresponding axis while traversing a pathdefined by a corresponding imaginary ray extending from the center ofthe circular base to that location in the first involute profile, thecorresponding axis being tangential to an imaginary circle thatencompasses the inner region of the surface and perpendicular to thecorresponding imaginary ray; (e) the first bracket being rotatable aboutthe first pivot at least within a first range of angles, the firstinvolute gear being rotatably coupled to the receiving portion of thefirst bracket such that the first involute gear and the first windowshade roller are rotatable about the central axis of the first involutegear, the first pivot being located at a first distance from the centralaxis of the first involute gear; and (f) the second bracket beingrotatable about the second pivot at least within a second range ofangles, the second involute gear being rotatably coupled to thereceiving portion of the second bracket such that the second involutegear and the second window shade roller are rotatable about the centralaxis of the second involute gear, the second pivot being located at asecond distance from the central axis of the second involute gear; and(g) wherein the first pivot is tangential to the imaginary circle of thefirst involute gear and is located at a first distance from the centralaxis of the first involute gear, the second pivot is tangential to theimaginary circle of the second involute gear and is located at a seconddistance from the central axis of the second involute gear and isparallel to the first pivot, and the first bracket and the secondbracket are interconnected such that a first angle formed between theinner region of the surface of the first gear and a mid-planeperpendicular to and bisecting an imaginary line extending from thefirst pivot to the second pivot, and a second angle formed between theinner region of the surface of the second gear and the mid-plane, eachhave a same value, so that for any angle within the first range ofangles, the gear tooth of the first involute gear meshes with the geartooth of the second involute gear at a corresponding angle within thesecond range of angles.